Owing to the absence of experiments that could test semi-classical gravity (or any other theory of quantum gravity) on an empirical level, considerations of interpretation have come to have great weight in assessing its viability. In the past few decades there have, in fact, been several influential arguments, first by Eppley and Hannah [1]}, later by Page and Geilker [2]}, as well as by Unruh [3]}, that sought to rule out semi-classical gravity on purely theoretical grounds.
